<template>
    <div class="login_container">
        <div class="login_box">
            <!-- 头像区域 -->
            <div class="avatar_box">
                <img src="../assets/logo.png" alt="">
            </div>
            <!-- 登录表单区域 -->
            <el-form ref="loginFormRef" label-width="" class="login_form" :model="loginForm" :rules="loginFormRules">
                <!-- 用户名 -->
                <el-form-item label="" prop="username">
                    <el-input placeholder="请输入用户名" prefix-icon="iconfont icon-user" v-model="loginForm.username"></el-input>
                </el-form-item>  
                <!-- 密码 -->
                <el-form-item label="" prop="password">
                    <el-input placeholder="请输入密码" prefix-icon="iconfont icon-3702mima" v-model="loginForm.password" type="password"></el-input>
                </el-form-item>
                <!-- 按钮 -->
                <el-form-item class="btns">
                    <el-button type="primary" @click="login">登录</el-button></el-button>
                    <el-button type="info" @click="resetLoginForm">重置</el-button>
                </el-form-item>
            </el-form>   
        </div>
    </div>

</template>
<script>
export default {
    data() {
        return{
            // 登录表单的数据绑定对象
            loginForm: {
                username: 'admin',
                password: '123456'
            },
            // 表单验证规则对象
            loginFormRules: {
                // 验证用户名
                username:[
                    { required: true, message: '请输入用户名', trigger: 'blur' },
                    { min: 3, max: 12, message: '长度在 3 到 12 个字符', trigger: 'blur' }
                ],
                // 验证密码
                password: [
                    { required: true, message: '您还未输入密码！', trigger: 'blur' },
                    { min: 6, max: 15, message: '长度在 6 到 15 个字符', trigger: 'blur' }
                ]
            }
        }
    },
    methods: {
        // 重置表单
        resetLoginForm: function(){
            this.$refs.loginFormRef.resetFields();
        },
        // 登录
        login: function(){
            this.$refs.loginFormRef.validate(async valid => {
                if(!valid) return;
                const{ data:res } = await this.$http.post("login", this.loginForm);
                if(res.meta.status !== 200) return this.$message.error({
                    showClose: true,
                    message: '登录失败，请检查用户或密码输入是否正确！',
                    duration: 1000
                })
                this.$message.success({
                    showClose: true,
                    message: '登录成功！',
                    duration: 1000
                })
                /**
                 * 1. 将登录成功之后的token 保存到客户端的 sessionStorage 中
                 *   1.1 项目中除了登录之外的其他api接口，必须在登录之后才能访问
                 *   1.2 token 只应在当前网站打开期间生效，所以将 token 保存在 sessionStorage 中
                 */
                window.sessionStorage.setItem('token', res.data.token);
                /**
                 * 2. 通过编程式导航跳转到后台主页，路由地址是 /home
                 */
                this.$router.push('/home')
            })
        }
    }
}
</script>

<style lang="less" scoped>
.login_container{
    background-color: #2b4b6b;
    height: 100%;
}
.login_box{
    width: 450px;
    height: 300px;
    background-color: #fff;
    border-radius: 3px;
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    .avatar_box{
        height: 130px;
        width: 130px;
        border: 1px solid #eee;
        border-radius: 50%;
        padding: 10px;
        box-shadow: 0 0 10px #ddd;
        position: absolute;
        left: 50%;
        transform: translate(-50%, -50%);
        img{
            width: 100%;
            height: 100%;
            border-radius: 50%;
            background-color: #eee;
        }
    }
}
.login_form{
    position: absolute;
    bottom: 0;
    width: 100%;
    padding: 0 30px;
    box-sizing: border-box;
}
.btns{
    display: flex;
    justify-content: center;
    align-items: center;
}
</style>